> I have no idea what is going on from the signature itself. Is records a list, a dict or a database connection? Is check a boolean, or a function? What does this function return? What happens if it fails, does it raise an exception, or return None? [...]

This type of objection is only raised by people who have never seriously used Python before. It sounds convincing that this is a serious flaw in Python, but in practice it never comes up because when you know what domain you're working in it's always immediately obvious what types the arguments are.